This porgram project grant consists of six interrelated projects directed by Drs. Roger Kornberg, Peter Parham, Peter Sargent, James Spudich, Lubert Stryer, and Nigel Unwin. The program focuses on the structure and function of membrane components. Membrane channels are being examined by Drs. Kornberg and Unwin, membrane receptors by Drs. Parham, Sargent and Stryer, and membrane anchors by Dr. Spudich. These porjects are related not only through a common concern with biological membranes, but also in the nature of the objectives and experimental approaches. In every case the goal is an understanding of membrane processes in terms of the 3-D organization of membrane constituents. Whenever posible, the organization will be pursued in molecular and atomic detail. The methods needed to attain these objectives are varied, and include biochemical fractionation and reconstitution, monoclonal antibody production, X-ray diffraction, electron microscopy, fluorescence, and image-processing. We are dependent on one another for expertise in these various approaches and have a common need of the diverse equipment and ancillary personnel involved.